The present invention generally refers to a surgical instrument for use in ophthalmic surgery, and in particular to an iris retractor for use in eye surgery of a living being for retraction of the iris.
Iris retractors are known which generally include an elongated body portion with a substantially hook-shaped end for retracting the iris, and a fixation member slidably mounted on the body portion for securing the iris retractor in place when the body portion is inserted with its hook-shaped end into the anterior chamber through a suitable incision made in the cornea.
It is well known that adequate dilatation of the pupil of the eye is essential during e.g. cataract surgery. In particular, for removal of a cataract, the surgical procedure in the posterior section as well as anterior section of the eye requires a sufficiently large and constant viewing range for the surgeon. Generally, the dilatation of the pupil is effected through administration of pharmaceuticals. However, on occasions, the use of pharmaceuticals is insufficient to attain the desired dilatation so that the use of surgical instruments for retracting the iris is proposed, e.g. application of one or more suitably spaced iris retractors which attach to the iris to pull it outwardly for enlarging the opening of the pupil. The individual iris retractors are inserted into the anterior chamber of the eye through an incision in the cornea and suitably fixed in tight manner by the fixation member at the outer contour of the eye. After surgery, the iris retractor is released from the iris and withdrawn from the anterior chamber of the eye.
European Pat. No. 0 653 197 describes an iris retractor for use in the ophthalmic surgery, with the iris retractor having a body portion formed at one end with a hook-shaped engagement member for insertion into the anterior chamber of the eye and withdrawal of the iris. A plate-shaped fixation member is slidably mounted to the body portion to hold the body portion in place in the region of the transition area from the cornea to the sclera.
U.S. Pat. No. 5,716,328 describes an iris retractor which includes an elongated body portion for insertion through an incision in the eye to retract the iris, with the body portion including two parallel shafts secured to each other along a common longitudinal edge wherein each shaft has at least one end formed with a hook-shaped member. The shafts of the body portion are so joined together that the hook-shaped members diverge from the longitudinal edge downward at an angle to one another to exhibit a .LAMBDA.-shaped configuration, and exhibit parallel shanks which are spaced from each other at a distance, the dimension of which depends on the angle between the hook-shaped members.
In both these conventional iris retractors, the individual body portion has a length of about 5 mm to 8 mm and is made of a flexible polymeric material with a diameter of about 0.15 mm to 0.20 mm, whereas the hook-shaped engagement member has a length of about 1.0 mm to 1.5 mm.
The use of such iris retractors for ophthalmic surgery in the anterior or posterior eye sections suffers, however, shortcomings as far as recognition is concerned. As a result of their relatively small size, the surgeon has oftentimes great difficulty to see the individual iris retractors during the process of inserting the retractors into the anterior chamber and attaching the retractors to the iris or removing them from the eye. This may potentially adversely affect the surgery.